A grommet structure in an incubator comprising a grommet attaching portion provided to an enclosure of the incubator and a grommet member attached to the grommet attaching portion, wherein the grommet member includes a longitudinal member holding incision to hold a longitudinal member such as an oxygen supply tube that extends therethrough, is conventionally known as disclosed in, e.g., International Publication WO 99/12512 (to be referred to as “the above prior patent reference” hereinafter). The grommet member employed the grommet structure disclosed in the above prior patent reference includes a comparatively thick substantially U-shaped attaching target member which is provided to the grommet member along the outer circumference (the entire outer circumference excluding the upper rim) of the grommet member. The substantially U-shaped attaching target member is attached to the grommet attaching portion of the enclosure of the incubator. Of the grommet member, a portion surrounded by the substantially U-shaped attaching target member is comparatively thin and constitutes a cable holder. In this DESCRIPTION, the “cable” refers to various types of longitudinal members such as a tube, cable and electric cord for various types of instruments, e.g., an oxygen mask used in the incubator, or various types of such longitudinal members as a bundle obtained by bundling a plurality of longitudinal members having the same or different diameters (including a case in which a jacket tube such as a bellows tube covers the bundle of the plurality of longitudinal members).
The cable holder of the grommet member of the above prior patent reference also has a cable holding incision formed of one vertical slit and a plurality of horizontal incisions. The vertical slit extends substantially vertically from the upper end of the holder to a region consisting of the lower end of the holder and its vicinity. The plurality of horizontal incisions extend substantially horizontally to be substantially perpendicular to the vertical incision. When the cable is to be held by the cable holder of the grommet member, the operator abuts an appropriate portion of the cable against the vertical incision from above and moves it downward by pushing it into the vertical incision. This introduces the cable into a substantially crisscross intersecting portion where the vertical incision and a horizontal incision intersect. Of the cable holder, four holding pieces that constitute the intersecting portion elastically position and hold the cable at a region consisting of the intersecting portion and its vicinity.
In the case of the grommet structure in the incubator disclosed in the above prior patent reference, as the cable must be elastically held in position at the crisscross intersecting portion (in other words, the four holding pieces) of the cable holder of the grommet member, the cable holder cannot be very thin. As the cable holder of the grommet member cannot be very thin, the four holding pieces of the cable holder have comparatively low elasticity. Therefore, the cable tends to be damaged by repeated slide friction with the four holding pieces. As the four holding pieces cannot position and hold the cable reliably, the cable tends to move downward (or upward depending on the case) along the vertical incision or in the longitudinal direction of the cable. Furthermore, as the cable is inserted in the cable holding incision, a large gap is formed among the four holding pieces. Then, a large amount of external air is introduced through the gap into the enclosure in the closed state.